Self adjusting pressure drive shaft

ABSTRACT

The roller assembly includes: a first shaft having a longitudinal axis; a self adjusting pressure drive shaft extending parallel to the longitudinal axis, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring. An apparatus for a continuously winding a transformer core in an electrical transformer includes: a feed assembly for a material, the feed assembly includes a first shaft disposed adjacent a self adjusting pressure drive shaft, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring.

BACKGROUND OF INVENTION

[0001] In the electronic industry, electrical transformers, e.g., current transformers, are often used in wide array of applications, including the use of electrical transformers with printed circuit boards and with circuit interruption devices. The electrical transformers are capable of providing power to the circuit board as well as sensing current in the primary circuit of the circuit board. In order for the electrical transformer to provide adequate power to the circuit board, the transformer has a high magnetic permeability core and the coil of the transformer has a high number of wire turns to provide the required voltage.

[0002] The core of the transformer may be wound on an apparatus that feeds flat stock material through an assembly procedure. The flat stock material is stored on a roll and is rolled out through the first station of the apparatus through a pinch roller assembly that feeds the material to the winding station of the apparatus. An encoder measures the appropriate amount of material for each core. One of the drawbacks of the present apparatus is that the material can slip as it passes through the pinch roller assembly. The slippage then provides erroneous information to the encoder. As a result, an incorrect amount of material is forwarded to create the transformer coil. Pinch roller assemblies have been mounted on spring loaded devices; however, the spring-loaded devices do not provide the flexibility to adjust in all directions when non-uniform flat stock material is fed through the apparatus.

SUMMARY OF INVENTION

[0003] The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a roller assembly for feeding flat stock material. In an exemplary embodiment, the roller assembly includes: a first shaft having a longitudinal axis; a self adjusting pressure drive shaft extending parallel to the longitudinal axis, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring. In an alternative exemplary embodiment, an apparatus for a continuously winding a transformer core in an electrical transformer includes: a feed assembly for a material, the feed assembly includes a first shaft disposed adjacent a self adjusting pressure drive shaft, the self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds the main body portion; and a flexible material is disposed between the main body portion and the ring.

BRIEF DESCRIPTION OF DRAWINGS

[0004] Referring now to the drawings wherein like elements are numbered alike in the several Figures:

[0005]FIG. 1 is a side view of a self adjusting pressure drive shaft;

[0006]FIG. 2 is a side view of a main body portion of the self adjusting pressure drive shaft of FIG. 1;

[0007]FIG. 3 is a side view of a ring of the self adjusting pressure drive shaft of FIG. 1;

[0008]FIG. 4 is a cross-section view of the ring of FIG. 3;

[0009]FIG. 5 is a side view of an apparatus for continuous core winding of electrical transformers utilizing the self adjusting pressure drive shaft of FIG. 1;

[0010]FIG. 6 is a top view of a section of the apparatus of FIG. 5;

[0011]FIG. 7 is a side view of a winding area of the apparatus in FIG. 5; and

[0012]FIG. 8 is a schematic drawing of the apparatus of FIG. 5 attached to a computer system.

DETAILED DESCRIPTION

[0013] Referring to FIGS. 1 and 2, a self adjusting pressure drive shaft 20 is illustrated. Self adjusting pressure drive shaft 20 includes a main body portion 22 and an extension 24. Main body portion 22 is cylindrical in shape and includes a first section 26 and two second sections 28. First section 26 has an outside diameter 30 that is smaller than an outside diameter 32 of second section 28. Preferably, first section 26 is located at a mid-point 34 of main body portion 22. First section 26 includes two shoulders 36 located adjacent to a first edge 38 of second section 28 and a second edge 40 of second section 28.

[0014] In an exemplary embodiment, outside diameter 30 of first section 26 is about 0.47 inches (1.19 mm) and outside diameter 32 of second section 28 is about 0.625 inches (1.59 mm); thus, outside diameter 30 is about 0.155 inches (0.39 mm) less than outside diameter 32. In addition, first section 26 has a length 42 of approximately 0.35 inches from edge 38 to edge 40.

[0015] Referring to FIGS. 1, 3 and 4, self adjusting pressure drive shaft 20 also includes a ring 50. Ring 50 has a circular shape with a hollow center 52 and a lip 54 located on either side of ring 50. Ring 50 is disposed at first section 26 and is mounted at shoulders 36. There is a space 56 between first section 26 and an inner diameter 58 of ring 50. Space 56 is filled with a flexible material 60, such as elastomeric, rubber, neoprene, or urethane. Space 56 allows flexible material 60 to be self retained on main body portion 22. Flexible material 60 may also be secured to ring 50 and/or to main body portion 22 by an adhesive so that ring 50 does not rotate independently from main body portion 22. Flexible material 60 can have varying durometer with a hardness value ranging from about 15 duro to about 90 duro. Within this range, the hardness value may preferably be up about 75 duro to about 80 duro. Flexible material 60 may be placed into space 56 in any manner, such as inserted, injected, or pressed. Ring 50 is made from a hard material such as steel, or the like. The material may also be heat treated so that it has a Rockwell C Hardness of about 50-56.

[0016] Self adjusting pressure drive shaft 20 may be incorporated into any apparatus that utilizes flat stock material. Referring to FIG. 5, in an exemplary embodiment, self adjusting pressure drive shaft 20 is incorporated into a core winding apparatus 100. Apparatus 100 allows a material 110 to be tightly wound into a core to form an electrical transformer. Material 110 is preferably made from a ferrous material. The ferrous material may include a silicon steel. Apparatus 100 includes a material storage area 120, which may include any type of conventional feeding devices. In an exemplary embodiment, material 110 is stored on a first reel 124. A second reel 126 is located adjacent to first reel 124 and holds material 110 on first reel 124 so that first reel 124 does not unwind. First reel 124 allows material 110 to uncoil as a strip and move to a pinch roller area 130. First reel 124 and second reel 126 are mounted to a frame 127. Frame 127 may be mounted to the floor or to a frame 128 of apparatus 100.

[0017] Pinch roller area 130 includes self adjusting pressure drive shaft 20 and a pinch roller 132 located on top of one another and contacting each other at a point 134. Pinch roller 132 may be any shaft type device that rotates to allow material 110 to feed through pinch roller area 130. While the exemplary embodiment illustrates self adjusting pressure drive shaft 20 as the roller on top of pinch roller 132, alternatively self adjusting pressure drive shaft 20 may be located on the bottom and pinch roller 134 may be located on top. Self adjusting pressure drive shaft 20 and pinch roller 132 act as a pair of pinch rollers. A servomotor 136 (see FIG. 6) is coupled to extension 24 of self adjusting pressure drive shaft 20, which rotates self adjusting pressure drive shaft 20 in a counterclockwise direction. While the rotational force to self adjusting pressure drive shaft 20 illustrated in the exemplary embodiment as servomotor 136, other means may be employed to generate the rotational force, such as, a stepping motor, standard motor, air power devices, and the like.

[0018] Pinch roller 132 is coupled to a spring 138, which biases pinch roller 132 towards self adjusting pressure drive shaft 20 and creates pressure between self adjusting pressure drive shaft 20 and pinch roller 132 at a point 134. Spring 138 may also be coupled to a pneumatic cylinder 140, which adjusts the tension in spring 138. In an exemplary embodiment, spring 138 presses against a first end 142 of an arm 144 and pneumatic cylinder 140 is coupled to a second end 146 of arm 144.

[0019] Pneumatic cylinder 140, which may be either manually or automatically regulated, may be adjusted to push against second end 146 of arm 144 so that arm 144 rotates in a counterclockwise direction so as to apply additional tension in spring 138. Pneumatic cylinder 140 can also be adjusted so that less pressure is applied against second end 146 of arm 144 so that arm 144 rotates in a clockwise direction, which in turn releases tension from spring 138. Alternatively, the force that is provided between self adjusting pressure drive shaft 20 and pinch roller 132 can be generated in a variety of other ways, including, mechanically, electrically, or by hydraulic means.

[0020] Material 110 is available in a variety of dimensions and in particular, is available in a range of widths and thicknesses. Moreover, as material 110 is fed through apparatus, material 110 can varying in thicknesses, as the material is not perfectly uniform. Referring to FIGS. 1 and 5, self adjusting pressure drive shaft 20 and pinch roller 132 are set to provide a certain amount of tension at point 134 so that material can be pulled through apparatus 100. When self adjusting pressure drive shaft 20 is assembled into apparatus 100, ring 50 pinches against the pinch roller 132 and contacts material 110. Because ring 50 is made from a hard material, ring 50 provides a proper amount of pressure against pinch roller 132 to feed material 110 through apparatus 100. However, because ring 50 is mounted on flexible material 60, the pressure between ring 50 and pinch roller 132 can adjust and flex in different directions for varying thicknesses of material 110.

[0021] Referring to FIG. 6, servomotor 136 includes an encoder 150 that measures a predetermined amount of material 110 being fed into pinch roller area 130. Optionally, apparatus 100 may also include an external encoder (not shown), which also measures the amount of material 110 that is being fed through pinch roller area 130. The external encoder may also serve as a backup system for encoder 150 included within the servomotor 136 so that the desired and appropriate amount of material 110 is fed through pinch roller area 130. Other known encoding devices may be used in combination with apparatus 100. Servomotor 136 also includes a controller 152 that allows servomotor 136 to be operated automatically.

[0022] Referring to FIGS. 5 and 6, material 110 moves from pinch roller area 130 to a cutter area 160. Cutter area 160 includes a cutter assembly 162 that is driven by pneumatic cylinders 164. Pneumatic cylinders 164 are adjusted to supply a certain amount of force so that cutter assembly 162 can cut material 110.

[0023] Referring to FIGS. 5 and 7, material 110 moves from cutter area 160 to a winding area 170. Winding area 170 includes a winding cavity 172, which can be divided into three movable quadrants 174, 176, and 178 and a fixed quadrant 180. As material 110 enters winding cavity 172, material 110 begins to wind in a circle. As more material 110 enters winding cavity 172, quadrants 174, 176, and 178 begin to move in an outwards direction to allow additional material to enter winding cavity 172. Quadrant 180 remains fixed and does not move.

[0024] Quadrant 174 is located at a top side 182 of winding cavity 172 and includes a side roller 184. A servomotor 186, which is coupled to side roller 184 by a linkage 188, drives side roller 184. Quadrant 174 is also coupled to a servomotor 190 by a linear slide 192. Servomotor 190 drives linear slide 192 and moves top side 182 away from a center 194 of winding cavity 172. Quadrant 176 is located at a right side 196 of winding cavity 172. Quadrant 176 is coupled to a servomotor 198 by a linear slide 200. Servomotor 198 drives linear slide 200 and moves right side 196 away from center 194 of winding cavity 172. Quadrants 174 and 176 are interlaced so that as quadrant 174 moves away from center 194 of winding cavity 172, quadrant 176 moves away from center 194 of winding cavity 172. Quadrant 178 is located on a bottom side 202 of winding cavity 172. Quadrant 178 is coupled to a spring loaded slide 204. As quadrant 176 expands away from center 194, quadrant 178 also moves away from center 194. Quadrant 178 moves at approximately half the speed as quadrant 176. Servomotors 186, 190, and 198 also include controllers 206, 208, and 210, respectively, so that servomotors 186, 190, and 198 can be controlled automatically.

[0025] Apparatus 100 also includes a plasma welder 220, which is mounted to a top side 222 of frame 128. Plasma welder 220 includes a hose 224 that is coupled with an opening 226 in quadrant 176. Plasma welder 220 utilizes argon gas to provide a spot weld on material 110 at the last turn of material 110 in winding cavity 172. The spot weld prevents material 110 from unwinding when it is removed from winding cavity 172. Alternatively, material 110 is secured by any suitable process. Other securing means include laser welding, resistance welding, case-welding, bonding, mechanically lancing or crimping, strapping the diameter of the coil, and the use of wire wraps.

[0026] Apparatus 100 operates in the following manner. Servomotor 136 energizes and turns self adjusting pressure drive shaft 20, which in turn causes pinch roller 132 to also turn. Self adjusting pressure drive shaft 20 and pinch roller 132 pull material 110 from first reel 124. Material 110 moves between self adjusting pressure drive shaft 20 and pinch roller 132 to cutter area 60. Material 110 will continue to move through cutter area 160 to winding area 170. After a predetermined amount of material 110 moves through pinch roller area 130, cutter 162 cuts material 110. In winding area 170, material 110 enters winding cavity 172 and pushes against the walls of winding cavity 172 to form a coil. As more material 110 enters winding cavity 172, quadrants 174, 176, and 178 expand to allow more material to enter winding cavity 172 and form the coil. Plasma welder 220 provides a spot weld on material 110 at the last turn of material 110 to hold material 110 in the coil and keep coil from unwinding. The formed coil drops out of winding cavity 172 and additional material 110 enters winding area 170 to begin a new coil.

[0027] Referring to FIG. 8, controllers 152, 206, 208, and 210 are operably coupled with a computer 300 by a data transmission media 302. Computer 300 is a suitable electronic device capable of accepting data and instructions, executing the instructions to process the data, and presenting the results. Therefore, computer 300 can be a microprocessor, microcomputer, a minicomputer, an optical computer, a board computer, a complex instruction set computer, an ASIC (application specific integrated circuit), a reduced instruction set computer, an analog computer, a digital computer, a molecular computer, a quantum computer, a cellular computer, a superconducting computer, a supercomputer, a solid-state computer, a single-board computer, a buffered computer, a computer network, a desktop computer, a laptop computer, a scientific computer, a scientific calculator, or a hybrid of any of the foregoing. While computer 300 is shown as being separated from apparatus 100, computer 300 can also be mounted to and/or integrated with apparatus 100.

[0028] Data transmission media 302 includes, but is not limited to, twisted pair wiring, coaxial cable, and fiber optic cable. Data transmission media 302 also includes, but is not limited to, radio and infrared signal transmission systems. Computer 300 is configured to provide operating signals to controllers 152, 206, 208, and 210 and to receive data from these components via data transmission media 302.

[0029] In addition to being coupled to controllers 152, 206, 208, and 210, computer 300 may also be coupled to external computer networks such as a local area network (LAN) 304 and the Internet. LAN 304 interconnects one or more remote computers 306, which are configured to communicate with computer 300 using a well-known computer communications protocol such as TCP/IP (Transmission Control Protocol/Internet Protocol), RS-232, ModBus, and the like. Additional apparatus 100 may also be connected to LAN 304 with the computers 300 in each of these apparatus being configured to send and receive data to and from remote computers 306 and other apparatus 100. LAN 304 is connected to the Internet via a server computer 308. This connection allows computer 300 to communicate with one or more remote computers 310 connected to the Internet.

[0030] Computer 300 is preferably controlled by a PC or PLC base processor. All electrical and mechanical components of apparatus 100 are integrated to achieve the best quality product that meets all predetermined specifications and achieves the most optimum manufacturing cycle. Because of possible variations of the thickness (tolerance) of material 110, at least one thickness measuring device (not shown) constantly measures the thickness of material 110 so that the exact length necessary is calculated to achieve the correct amount of material 110 to winding area 170. As is known in electrical transformer technology, the amount of material 110 (surface area) of the coil is related to the current output of the transformer.

[0031] Self adjusting pressure drive shaft 20 provides the necessary latitude to feed material 110 with precision and in a reliable manner. Because flexible material 60 is inserted between main body portion 22 and ring 50, self adjusting pressure drive shaft 20 has the flexibility to adjust in all directions while still maintaining the required force to pinch material 110 so that material 110 can be displaced forward through apparatus 100 when self adjusting pressure drive shaft 20 is rotated. Moreover, self adjusting pressure drive shaft 20 compensates axially to the forces applied as material 110 passes through pinch roller area 130. In addition, the utilization of self adjusting pressure drive shaft 20 as part of a material feeding system provides the accuracy required to calculate an accurate amount of material 110 that passes through pinch roller area 130.

[0032] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. 

1. A roller assembly for feeding flat stock material comprising: a first shaft having a longitudinal axis; a self adjusting pressure drive shaft extending parallel to said longitudinal axis, said self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds said main body portion; and a flexible material is disposed between said main body portion and said ring.
 2. The assembly of claim 1, wherein said main body portion has a first section and a second section, said first section has a smaller diameter than said second section.
 3. The assembly of claim 2, wherein said flexible material is disposed at said first section.
 4. The assembly of claim 1, wherein said flexible material is made from a material selected from a group consisting of elastomeric, rubber, neoprene, and urethane.
 5. The assembly of claim 1, wherein said flexible material includes a hardness value of about 15 duro to about 90 duro.
 6. The assembly of claim 1, wherein said ring is made from steel.
 7. The assembly of claim 1, further comprising an extension extending from said main body portion.
 8. The assembly of claim 1, wherein said first shaft and said ring contact at a point, said point having a predetermined amount of pressure.
 9. An apparatus for continuously winding a transformer core in an electrical transformer, said apparatus comprising: a feed assembly for a material, said feed assembly includes a first shaft disposed adjacent a self adjusting pressure drive shaft, said self adjusting pressure drive shaft includes: a main body portion having a cylindrical shape; a ring surrounds said main body portion; and a flexible material is disposed between said main body portion and said ring.
 10. The apparatus of claim 9, wherein said main body portion has a first section and a second section, said first section has a smaller diameter than said second section.
 11. The apparatus of claim 10, wherein said flexible material is disposed at said first section.
 12. The apparatus of claim 9, wherein said material is a flat stock material.
 13. The apparatus of claim 9, wherein said flexible material is made from a material selected from a group consisting of elastomeric, rubber, neoprene, and urethane.
 14. The apparatus of claim 9, wherein said flexible material includes a hardness value of about 15 duro to about 90 duro.
 15. The apparatus of claim 9, wherein said ring is made from steel.
 16. The apparatus of claim 9, wherein said feed assembly further comprises a spring coupled to said first shaft, said spring providing tension at a point of contact between said first shaft and said self adjusting pressure drive shaft.
 17. The apparatus of claim 16, wherein said feed assembly further comprises a pneumatic cylinder coupled to said spring, said pneumatic cylinder controlling an amount of tension at said point.
 18. The apparatus of claim 9, further comprising an extension extending from said main body portion.
 19. The apparatus of claim 18, further comprising a motor coupled to said extension.
 20. The apparatus of claim 19, wherein said motor includes a controller.
 21. The apparatus of claim 19, wherein said motor includes an encoder.
 22. The apparatus of claim 19, wherein said motor is a servomotor.
 23. The apparatus of claim 9, further comprising a cutting device for cutting said material at a predetermined point.
 24. The apparatus of claim 9, further comprising a winding area for continuously winding said material through an opening. 